Is there a best model? A radioecological case study

Mathematical models are extensively used to support decision-making in many disciplines. Nevertheless there are not clear standard guidelines to assess models performance. This significantly affects model selection processes, which aim to determine the "best model", among several possible...

Full description

Bibliographic Details
Main Author: Tarsitano, Davide
Format: Thesis (University of Nottingham only)
Language:English
Published: 2005
Subjects:
Online Access:https://eprints.nottingham.ac.uk/10202/
_version_ 1848791049071230976
author Tarsitano, Davide
author_facet Tarsitano, Davide
author_sort Tarsitano, Davide
building Nottingham Research Data Repository
collection Online Access
description Mathematical models are extensively used to support decision-making in many disciplines. Nevertheless there are not clear standard guidelines to assess models performance. This significantly affects model selection processes, which aim to determine the "best model", among several possible candidates. Model performance is often measured by the accuracy with which models predictions fit independent observations. However this test assesses only a single aspect of a model. A model selection process should establish the similarities between the constructed and the conceptual model. Therefore it should be based on a comprehensive assessment of the models capabilities, which is the objective of the multi-aspect comparison approach proposed in this work. The innovative aspect of this approach is to create a relationship among four conventional tests, i.e. uncertainty and sensitivity analysis, goodness-of-fit prediction-observations, model complexity and level of details, in order to provide a reliable estimation of the differences between the constructed and conceptual models. Although, model complexity is quantified using a standard approach, a novel methodology is proposed in this thesis, intended to be an intuitive and illustrative approach in creating a linkage between model complexity and level of detail. Five radioecological models have been considered: SAVE rural model, TEMAS rural model, SAVE semi-natural model, FORM and RIFE1. The results show that there is a limited resemblance between these models and the respective conceptual models. This is due to low prediction accuracy (RIFE1 and FORM); high level of uncertainty (SAVE rural); sensitivity to parameters which is not consistent with the current understanding of radiocaesium behaviour in the environment (TEMAS and SAVE rural). The SAVE rural model has been revisited in order to increase the similarity between the constructed and conceptual model. The resulting model prediction shows lower degree of uncertainty and there is a significant agreement between the model sensitivity results and the general understanding of the processes affecting Cs soil-to-plant transfer. Nonetheless the revised model does not show higher prediction accuracy than the original model. It is concluded that a reliable methodology for model selection should be based on a comprehensive investigation of each considered model aspect and that there is not a single best approach. The methodology proposed in this work has been successful in the case of the five radioecological models studied.
first_indexed 2025-11-14T18:22:19Z
format Thesis (University of Nottingham only)
id nottingham-10202
institution University of Nottingham Malaysia Campus
institution_category Local University
language English
last_indexed 2025-11-14T18:22:19Z
publishDate 2005
recordtype eprints
repository_type Digital Repository
spelling nottingham-102022025-02-28T11:07:31Z https://eprints.nottingham.ac.uk/10202/ Is there a best model? A radioecological case study Tarsitano, Davide Mathematical models are extensively used to support decision-making in many disciplines. Nevertheless there are not clear standard guidelines to assess models performance. This significantly affects model selection processes, which aim to determine the "best model", among several possible candidates. Model performance is often measured by the accuracy with which models predictions fit independent observations. However this test assesses only a single aspect of a model. A model selection process should establish the similarities between the constructed and the conceptual model. Therefore it should be based on a comprehensive assessment of the models capabilities, which is the objective of the multi-aspect comparison approach proposed in this work. The innovative aspect of this approach is to create a relationship among four conventional tests, i.e. uncertainty and sensitivity analysis, goodness-of-fit prediction-observations, model complexity and level of details, in order to provide a reliable estimation of the differences between the constructed and conceptual models. Although, model complexity is quantified using a standard approach, a novel methodology is proposed in this thesis, intended to be an intuitive and illustrative approach in creating a linkage between model complexity and level of detail. Five radioecological models have been considered: SAVE rural model, TEMAS rural model, SAVE semi-natural model, FORM and RIFE1. The results show that there is a limited resemblance between these models and the respective conceptual models. This is due to low prediction accuracy (RIFE1 and FORM); high level of uncertainty (SAVE rural); sensitivity to parameters which is not consistent with the current understanding of radiocaesium behaviour in the environment (TEMAS and SAVE rural). The SAVE rural model has been revisited in order to increase the similarity between the constructed and conceptual model. The resulting model prediction shows lower degree of uncertainty and there is a significant agreement between the model sensitivity results and the general understanding of the processes affecting Cs soil-to-plant transfer. Nonetheless the revised model does not show higher prediction accuracy than the original model. It is concluded that a reliable methodology for model selection should be based on a comprehensive investigation of each considered model aspect and that there is not a single best approach. The methodology proposed in this work has been successful in the case of the five radioecological models studied. 2005 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/10202/1/DTarsitano_PhD2005.pdf Tarsitano, Davide (2005) Is there a best model? A radioecological case study. PhD thesis, University of Nottingham. Radioecological Model Uncertainty Analysis Sensitivity Analysis SAVE RIFE1 TEMAS FORM Model Complexity
spellingShingle Radioecological Model
Uncertainty Analysis
Sensitivity Analysis
SAVE
RIFE1
TEMAS
FORM
Model Complexity
Tarsitano, Davide
Is there a best model? A radioecological case study
title Is there a best model? A radioecological case study
title_full Is there a best model? A radioecological case study
title_fullStr Is there a best model? A radioecological case study
title_full_unstemmed Is there a best model? A radioecological case study
title_short Is there a best model? A radioecological case study
title_sort is there a best model? a radioecological case study
topic Radioecological Model
Uncertainty Analysis
Sensitivity Analysis
SAVE
RIFE1
TEMAS
FORM
Model Complexity
url https://eprints.nottingham.ac.uk/10202/